A number of electronic devices have graphical user interfaces (GUIs). Such devices include, for example, personal computers (PC), televisions and mobile telephones. The user may interact with the device via the GUI using a user interface, for instance a touch sensitive pad, a keyboard, a mouse or a joystick. Many factors determine the most appropriate choice of user interface for a device, such as ease and speed of operation and the environment in which the device is used. The use of a mouse is suited to the selection of icons when using a desk-top personal computer, however it is not so useful when used to make selections when using a digital television set. For this, a remote control unit having several keys is most convenient.
However, there are problems with using a key- or button-based control units as will now be explained with reference to digital television.
Digital television provides a variety of new services as compared with analogue television. It allows the user to transmit and receive signals via a set-top box and to interact with service providers. The user may now access the Internet in a similar way that is already available on a PC. For example, a user may navigate web pages by selecting hypertext links. The process of selecting a particular link involves moving a focus between links and activating selection. In a PC-based system, this process is realised by positioning a mouse pointer over the link and pressing the mouse button. To indicate that the focus has moved to the link, the shape of the mouse pointer changes or the link is highlighted, for instance, by changing colour.
The set-top box/television system is controlled using a remote control unit, which is similar to that used with present analogue televisions. The remote control is usually provided with a set of arrow keys—up, down, right, left—allowing orthogonal movement about a menu.
Such a remote control unit provides a satisfactory means for selecting elements of the menu if the menu is arranged as a rectangular array along co-ordinates defined by the keys on the remote control. Elements in a column are selected by the use of up and down buttons, while elements along a row may be selected by use of right and left keys. Thus, movement from one element to another is intuitive and reversible.
However, such a remote control unit is not suited to the selection of non-regularly positioned elements, such as links in a web page. Hypertext links may be represented by text or images and are located on the page according to as and when they are needed. Thus, it is most unusual for links to be arranged in a periodic array. If the focus is set on a highlighted link and there is no other link in the same row, pressing the right button on the remote control may result in an unexpected selection. Even more irksome is that subsequently pressing the left arrow key does not return the focus back to the original highlighted link, but to an entirely new link. Thus, movement from one element to another is non-intuitive and may be non-reversible.
The present invention seeks to solve this problem.